The patches work perfectly in the 1955 mod; in addition to the head-movement patch I also added the pit-stop patch, as it wasn't unknown for such stops to occur in the long races of the '50's......more for tyres rather than fuel, though.

However, the GT mod does not like the pit-stop patch (I didn't add the head patch to this mod) and pops up a postage stamp-sized error window saying......."ERROR"! (and no amount of clicking OK or the X will get rid of that pop-up......Task Manager has to be invoked to close GEM+ and/or the applicable GPL .exe file).

And some other ('66, '65', CanAm, for example) mods don't like either patches and pop that same little error window up.

I have created an Option folder for each mod under Mods/Gem+ etc, as per instructions. Obviously it works fine with the 1955 mod, so why not with the others?

I have just tried "77c Pit Stop v1.00" with my GT mod install and it works ok on my (Windows 10) PC. Sorry I don't know what might cause your problem for specific mods. I have never seen that "ERROR!" window.

When using the Pit Stop Patch, be certain that you are using version 1.01 and not version 1.07. The later patch is a fuel and tires pit stop patch. It only works properly with the 55Mod and beta 37Mod.

I don't think v1.01 has ever been publicly released. Only v1.00 (the version on Lee's website). Not sure if they are the same or just some slight difference. The v1.07 was included with the LoG mod and as you mentioned previously elsewhere should not be used.

I just checked and the Pit Stop is definitely the 1.0 patch as available on Lee's site. No other Pit stop patch is listed there.
I'll try installing the patches on my other PC (Windows 10) and see if it has the same problem.